Easy gold
At the start of the game when you reach the tutorial with the first shopkeeper, buy from him, and purchase the Paladin Tunic. The price of the tunic should be 0 gold and the selling price will be 1 gold. You can keep buying and selling it as long as desired. Note: This was done with version 1.18.6718, using a Monk.

Easy custom items for multi-player
Use the tool set to create a Module and then an Area. Make sure you are familiar with how to use it (making a start area, how to use tile sets, how to use the wizards). Export a character from any game (single or multi-player mode) that you wish to use in another multi-player game. Create the items at a low enough level so that your character can use them. You can check the level on the Properties/General menu of the item. Be aware that certain abilities will add a certain amount of Required Levels to the item. The easiest way is to use the wizard and create the item at your level, at Godly quality. Make sure after you create the item you have checked as being "Identified" or else you will not be able to use the item (unless your Lore is high enough). This can be found under the Properties/Properties menu, where you place the abilities. After you are done making you item, place it on the ground anywhere you desire. Nearest to the start location is best, and it is easiest to put them all inside a container of some sort, so you can just take them and place them directly into your inventory. Save the Module, Run the Module under New/CustomModule, then use the character that you exported (called a Local Character). You can now have custom items, names, colors, and abilities to your choosing. Export the character again, then play in a multi-player game. This does not appear work for a single player mode game.

Easy battles
An easy and effective strategy when fighting Bosses or other hard to kill creatures is to make them follow you until you reach an area transition door. Fight close to it and when your hit points are low, exit. The creature will not follow you through the door. Rest and save; then go back to fight. Normally the creature will not have regenerated. This trick can also work with normal doors depending on the monster; normally humanoid creatures will be able to open non-area transition doors.

Cheat Codes
Note: This procedure involves editing a game file; create a backup copy of the file before proceeding. Use a text editor to edit the "nwn.ini" file in the game folder. Add the following line under the "Game Options" section:

Debug Mode=1
Then while playing a game, press ~ and type "DebugMode 1" (case sensitive) to enable cheat mode. Then, press ~ again and press [Tab] to view the debug commands. Press [Tab] to scroll through the commands. Enter one of the following case-sensitive codes to activate the corresponding cheat function. If you entered the code correctly, the message "Success" will appear. If the message "Entered Target Mode" appears, click on the desired character to apply the cheat.

Note: If you alter your character, load the "nwnplayer.ini" file in the game folder and set the following lines in order to continue past the module you are currently on:

Single Player Enforce Legal Characters=0
Single Player ItemLevelRestrictions=0